Improving Firefighter Safety in the Wildland-Urban Intermix


Each year, the incursion of private residences in wildland, increases the chance that wildland and structural firefighters will battle an uncontrolled fire in the "Wildland-Urban Intermix", where homes and naturally occurring vegetation are the fuels at risk.

While the natural fuel types of these fires may differ based on geographic and climatic conditions, one factor remains constant: the risk to firefighters.

Four distinct groups are key players in the Wildland-Urban Intermix. Their relationship to firefighter safety - before an ignition and once a fire is burning - is critical. These groups include the community, the home owners, the fire agency, and individual firefighters.

Defining the Players

The Community

For this paper the 'community' is defined as the level of government that is responsible for laws, regulations, statutes, and ordinances that control developments, planning, and law enforcement in areas defined as intermix.

Perhaps the most important function the community can play to ensure firefighter safety is through planning. By requiring developers and builder to adhere to strict standards for building materials, clearing limits, and fire resistant plant species for landscaping, the community can help ensure that firefighters have a reasonable chance to safely fight a fire.

Access is a critical component of suppressing any fire, and becomes even more critical in wildland-urban intermix fires. Road width, traffic flow, curve radius, and bridge weight limits all impact on the timeliness and ability of fire apparatus to reach a fire, or to gain access to protect a structure.

The Homeowner

The homeowner who chooses to live in the intermix has an important role. The choice of the construction design and building materials can significantly affect a residence's fire safety. Maintaining the defensible space, reducing naturally occurring hazards, and preventing unwanted fires are all responsibilities of the homeowner.

The Fire Agency

The overall responsibility for ensuring the safety of firefighters lies with the agency having jurisdiction for the area. Once a fire ignition occurs, it is too late to take steps that are essential to ensure a safe and efficient fire suppression operation.

Communications have always been identified as a critical component in firefighter safety. In the wildland-urban intermix environment the capability of a communications system to function across jurisdictional boundaries is even more critical. These fires nearly always involve numerous fire agencies, often operating under a unified command structure. Agencies must provide their firefighters with communication systems capable of functioning in these environments. Failure to do so threatens firefighter safety and limits their ability to perform effectively. Communications failures or overload have been identified as a serious problem on both the Oakland Hills fire (California) and the Spokane, Washington Firestorm fires in 1991, and as a causal factor of the 1993 Glenallen Fire fatalities in Los Angeles County.

Physical fitness, the physical ability to do the job at hand, is another key area where fire agencies can have a positive influence on firefighter safety. Heart attacks were among the leading causes of firefighter fatalities (21%) on both wildfires and structural fires in the USA during the 1990's.

Another area where fire agencies have a major role in fire fighter safety is in developing policies and standard operating procedures (SOP's) specific to the wildland-urban intermix fire operations.

The Firefighter

Firefighters are the most critical players in affecting their own safety on wildland-urban intermix fires. Shakespeare said :"To thine own self be true." This is especially applicable to the individual firefighter. Although many actions of the community, homeowner, and fire agency can help ensure firefighters' safety, firefighters as individuals, or as members of a team, are ultimately responsible for their own safety.

Firefighters have the responsibility to ensure they are physically fit for the job. They also have an individual responsibility to use appropriate personal protective equipment (PPE).

The best training is wasted if the individual involved is unable to apply that training and respond appropriately. Situational awareness - knowing what is happening around you - is important if they are to safely and efficiently perform their job.

All firefighters, regardless of their position in the fire organisation, must do all they can to foster communications with other individuals above and below them.

Maintaining constant communications is a cornerstone of fire safety.

During the Fire

Up to this point, we have discussed firefighter safety before a wildland-urban intermix incident occurs. Once such a fire starts, a whole new group of factors come into play.


Access can quickly become a critical factor once a fire occurs. If the civilian population is attempting to leave an area on the same roads that firefighters are using to enter the area, the result can be traffic jams, unsafe driving practices, and ultimately, gridlock for both civilian vehicles and the fire appliances. When this occurs during active fire behaviour, firefighters may become trapped in dangerous locations, as they were in the Calabasas Incident in Los Angeles County during the 1996 fire season. On that incident, firefighters trying to cross a midslope road were prevented from leaving a "chimney" by a civilian vehicle attempting to leave the area. When the fire made a strong uphill run through the chimney, the firefighters were burned over.

Local firefighters may need to be assigned with firefighters from other areas to help them move throughout the fire area.

Civilian Population

It is likely that the majority of residents threatened by a wildland-urban intermix fire will be grossly unprepared for evacuation. Some will be unwilling to leave their property. Their chaotic exodus, or their refusal to leave, may pose a serious risk to firefighter safety.

Special Hazards

Firefighters entering the wildland-urban intermix area for fire suppression activities face a variety of hazards that differ from the typical hazards in either wildfires or structural fires. Although intermix fires appear to be simply wildfires that threaten to burn residences, such fires represent unique, high-risk hazards that require special attention to prevent injury or death.

Mix of Forces

Nearly every wildland-urban intermix fire results in responses from a number of fire agencies, both wildland and structural. Unless properly co-ordinated, the mix of forces that responds to a fire can be a risk to firefighter safety. The variety of equipment, differing levels of training and experience, and the integration of hand crews, mechanized equipment, and air operations all offer opportunities for a breakdown in safe work practices. In that environment, firefighters and fire officers must be especially alert to the co-ordination required in using this mix of forces, and must follow their own agency's safe practices and procedures despite differences with the practices and procedures used by co-operators.

Command and Control

The command and control of intermix fires is often complicated. Factors that can cause confusion and conflicts and increase risk to firefighter safety include:

Close and timely co-ordination of responsible agencies is essential as soon as intermix fires occur. Although much of the needed co-ordination can take place during the off season, the critical interchange of information and agreements on operating procedures must occur on the fire ground between the designated fire officers from each involved agency. Especially sensitive areas include:

Failure to adequately plan and execute the steps necessary to ensure firefighter safety in the wildland-urban intermix has resulted in close calls, injuries and fatalities:


Fires in the wildland-urban intermix will occur more and more frequently. Co-ordinated efforts between the community, homeowners, fire agencies, and firefighters before the fire occurs are essential to ensure firefighter safety. These measures must be reinforced by safety-conscious performance by both firefighters and fire officers once fires are being fought in the wildland-urban intermix.

Dick Mangan

USDA Forest Service
Technology and Development Program
Missoula, Montana.

February 2000